Detector Characteristics

Currently a Reticon CCD (referred to as CCD-9 or Dewar#9)
is the only detector available for the Nickel Spectrograph. Dewar#9
is a 400 x 1200 thinned array with 27 micron pixels. The detector is
UV flooded to increase sensitivity and make the response more uniform.

Pixel scale is about 2 arcsec/pixel when using the 110mm lens (4
arcsec/pixel for 58mm lens). The field of view is approximately 3.6 x
3.6 arcminutes in direct imaging mode. The orientation in the image
display window is North up and East to the right.

We recommend using
the 110mm lens, no binning, and slow readout speed for all data
acquisition.

Readnoise and gain for each binning and readout mode is listed below.

Binning

ReadoutSpeed

Gain(e-/DN)

Readnoise(e-)

Readout Time(sec)

Linear to(DN)

x1

slow

0.6

8.0

11

45,000

x1

fast

0.6

69

3

45,000

x2

slow

0.6

5.6

3

50,000

x2

fast

Mode not usable,
bias level > 25,000 DN.

x4

slow

0.7

7.6

1

50,000

x4

fast

Mode not usable,
bias level > 25,000 DN

Fast readout mode is not recommended for use.
Baseline bias should be about 1000 DN (unless otherwise noted).
Measured on telescope by E.Gates Sept 2010.

The CCD full well depth is 80,000 e-.

The CCD is read out using a single amplifier. The 32 column
overscan region occupies the far right (highest numbered) columns.